Alloy



Patented Feb. 21, 1939 PATENT OFFICE ALLOY Anthony G.' de Golyer, NewYork, N. Y.

No Drawing. Application November 9, 1937, Serial No. 173,597

3 Claims.

The present invention relates to a new and useful alloy containingboron, titanium, tungsten and nickel, which is characterized by beingresponsive to thermal treatment for the improve- 5 ment of physicalproperties.

An object of thepresent invention is to provide an alloy especiallyadapted for use as metal cutting tools, the cutting eiiiciency of whichis superior to that of heretofore known high speed tools and otheralloys. A further object is to provide an alloy which is free from orsubstantially free from carbon and which is readily amenable to thermaltreatment by means of which the hardness, cutting efiiciency, resistanceto deformation and other physical properties and characteristics can beaccurately controlled over a comparatively wide range.

I have found through experiment that by alloying or otherwise intimatelycombining boron, ti-

tanium, tungsten and nickel within the range boron 0.50% to 4%, titanium0.25% to 7%, tungsten 2% to and nickel substantially the balance that Iobtain metallic compositions which are readily responsive to thermaltreatment by 5 means of which the physical properties andcharacteristics can be developed and controlled.

I have found that molybdenum or uranium may be used to supplant all or aportion of the tungsten of the alloy.

30 Alloys of this invention may be used in the cast condition forcertain purposes, but approximate maximum values of hardness, resistanceto deformation and certain other important physical properties can bedeveloped only through ther- 5 mai treatment or through mechanicalworking and thermal treatment. Bodies of the alloy which have beensubjected to such treatment are particularly valuable for use as tools,dies and the like for the cutting or mechanical working of metals, aswell as for many other industrial uses.

The present alloy is particularly responsive to thermal treatment forthe development of precipitation hardening and I usually prefer tosubject the alloy to such thermal treatment before using it for metalcutting tools, dies, etc. As an illustration, cast bodies of the alloymay have a hardness of from to 5'7 on the Rockwall C scale-and bysubjecting the material to suitable so thermal treatment such as heatingto a temperature higher than approximately 1000 C., followed by rapidquenching, the hardness can be glowe'redito an approximate range of from35 to 45 Rockwell C. The alloy can subsequently be 5, subjected to asecond thermal treatment, such as heating to a temperature lower than1000 C. for one hour or more, followed by cooling at a normal rate by-which the hardness can be increased to from approximately 58 toRockwell C. An important property of the alloy is that 5 virtually allof the maximum hardness developed by thermal treatment is retained whenthe alloy is subjected to temperatures between 500 C. and 750 C. forlong periods in various industrial operations. 10

Bodies of the alloy which have been subjected to a suitable thermaltreatment are particularly resistant to abrasion at normal and elevatedtemperatures, and are also remarkably resistant to failure from suddenor repeated shock and to 15 mechanical deformation. Consequently,cutting tools, dies and other articles composed of the present alloyretain an efficient cutting edge or working face for unusually longperiods of time.

The more important distinctive advantages are 20 apparently due to thepresence of appreciable amounts of boron in the composition, inconjunction with the other components within the percentages specifiedherein.

I have found that chromium may be used as 25 an essential component inthe present alloy in an amount from 1% to 15%. 4

Specific examples of compositions within the scope of the presentinvention which I have found well adapted for numerous industrialapplica- 30 tions are the following: Boron 1.75%, titanium 3.60%,tungsten 17%, nickel substantially the balance; boron 2.15%, titanium1%, molybdenum 14%, nickel substantially the balance; boron 2.45%,titanium 1.50%, tungsten 4%, chromium 35 14%, nickel substantially thebalance.

An object of the present invention is to provide an alloy having highhardness, valuable metal cutting properties, etc. which is free from orsubstantially free from carbon and thus eliminate all 40 of the seriousdisadvantages associated with carbon containing alloys or compositionsintended for metal cutting tools, etc. Although I prefer to have thealloys entirely free from carbon, in many instances I have found carbonpresent in the nature of an impurity incidental to manufacture. It isimportant, however, to restrict the carbon content to a maximum of about0.15%, as I have found that the presence of higher per- 6 centages ofthis element not only act to embrittle the alloy but also inhibit orretard the desired or necessary reactions during thermal treatment.Furthermore, the presence of appreciable amounts of carbon decreases thered hardness of the alloy'when it is used as a metal cutting tool.

My investigationsindicate that the preferred structure of a body of thepresent alloy, particularly' after thermal treatment, comprises at leasttwo principal constituents; one, a relatively hard intermetalliccompound of boron with one or more of the other essential components;and two, a solid solution of two or more of the essential componentswhich has a lower degree of hardness and functions as a matrix. Theratio 01 the constituents, as well as ratio of particle size in any bodyof the alloy maybe accurately controlled and fixed over a wide range bymeans of thermal treatment.

By the term balance nickel in the foregoing and in the following claimsI intend that the alloy 01 the present invention comprise all of theessential components, other than nickel, within the limits specifiedherein with the remainder nickel, except for substantially ineffectualamounts of impurities which may be present incidental to manufacture.

I claim:

1. A precipitation hardened alloy containing boron 0.50% to 4%, titanium0.25% to 7%, metal selected from the group tungsten, molybdenum anduranium 2% to 30%and the balance nickel.

2. A precipitation hardened alloy containing boron 0.50% to 4%, titanium0.25% to 7%, tungstem 2% to 30% and the balance nickel.

3. A precipitation hardened alloy containing boron 0.50% to 4%, titanium0.25% to 7%. molybdenum 2% to 30% and'the balance nickel.

Ami tom? GI m: GOLYER.

